We have eCommerce sites in 6 different countries and have had schema mark up for product data for a couple of years. However the Price snippets do not display for our sites in Indonesia and Thailand, but work fine for our sites in Malaysia, Philippines, Singapore and Vietnam.
I noticed that we weren't including the SKU number in our mark up, which is a requirement according to Google specs, so we recently updated our Mark up to include the SKU and also changed from Microdata mark up to using JSON mark up (for ease of implementation).
However after waiting two weeks after implementation (for SERPs to update) we see for Indonesia and Thailand the price is still not displaying for single product mark up, but is appearing when we have multiple offers on a product page. (this is a new feature, we did not used to have mark up when we had multiple offers).
Below are two screen shots from the SERPs for our Thai and Indonesian site, showing the price appearing for multiple offers but not for single products.
If you click the links below you will see that the price appears on both single and multiple offers pages on our Malaysia, Philippines, Singapore and Vietnam sites.
There are no errors for Structured Data in Search Console and no errors when testing pages with Google's structured data testing tool. There is no difference in the mark up code between the different country sites.
So my question is why historically have we never had price appearing for our Thai and Indonesian sites, and why are we only getting it on pages with multiple offers now?